Anatomy - Upper limb Flashcards
What is the origin of the brachial plexus?
anterior rami of C5 to T1
What are the sections of the brachial plexus?
roots, trunks, divisions, cords, branches
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where are the roots of the brachial plexus?
posterior triangle
exits from IV foramina
between scalenus anterior and medius
where are the trunks of the brachial plexus?
posterior to the middle third of the clavicle
upper and middle trunks are superior to the subclavian artery
lower trunk passes over the 1st rib posterior to the subclavian artery
where are the divisions of the brachial plexus?
axilla
what are the cords of the brachial plexus related to ?
axillary artery (second part)
what is erbs paralysis?
damage to the upper nerve roots (c5, c6)
Motor affection (waiters tip) - arm adduction, internal rotation and forearm extension
sensation affection - loss of sensation of radial side of arm and forearm
which muscles are affected in erbs paralysis?
arm adduction - supraspinatus and deltoid
arm internal rotation (paralysis of external rotators) - infraspinatus and tires minor
forearm extension and pronation (loss of flexors and supinators) - biceps, brachialis, brachioradialis
what is klumpkes paralysis?
injury to the lower trunk (c8, t1)
motor affection - claw hand deformity
sensory affection - loss of sensation over the ulnar border of the forearm and hand
what muscles are affected in klumpkes paralysis?
claw hand
intrinsic muscles of hand
paralysis of wrist flexors (except FCR)
hyperextension of MCP joints with flexion of IP joints
what is the origin of pec major?
clavicular head - medial half of anterior surface of clavicle
sternocostal head - anterior sternum, upper 6 costal cartilages, EOA
what is the insertion of pec major?
humerus (lateral ITG)
what is the action of pec major?
adduction and medial rotation of the arm (all)
clavicular head - flexion of the arm
sternocostal head - extends the flexed arm
acts as accessory respiratory by elevating ribs
what is the innervation of pec major?
medal (c8-t1) and lateral (c5-c7 pectoral nerves)
what is the origin of trapezius?
spinous processes C7-T12
occipital protuberance
ligamentum nuchae
what is the insertion of trapezius?
clavicle and scapula (acromion and spine)
what is the action of trapezius?
rotating scapula
what is the innervation of trapezius?
accessory nerve CNXI
what is the origin of serrates anterior?
ribs 1-9
what is the insertion of serrates anterior?
scapula (ventral, medial)
what is the action of the serratus anterior?
prevents winging of scapula
what is the innervation of serratus anterior?
long thoracic nerve (c5-c7)
what is the origin of deltoid?
lateral clavicle, scapula
what is the insertion of deltoid?
humerus (deltoid tuberosity)
what is the action of deltoid?
anterior fibres - flexion and medial rotation
posterior fibres - extension and lateral rotation
middle fibres - major abductor of the arm beyond 15 degrees
what is the innervation to deltoid?
axillary nerve (c5, c6)
what are the rotator cuff muscles?
subscapularis, supraspinatus, infraspinatus, teres minor
what is the origin of subscapularis?
ventral scapula
what is the insertion of subscapularis?
humerus (LT)
what is the action of subscapularis?
internal rotation of the arm
anterior stability
what is the innervation to subscapularis?
upper and lower sub scapular nerves
what is the origin of supraspinatus?
superior scapula (supraspinatus fossa)
what is the insertion of supraspinatus?
humerus (GT)
what is the action of supraspinatus?
abduction, externally rotation arm
providing stability
what is the innervation to supraspinatus?
supra scapular nerve
what is the origin of infraspinatus?
dorsal scapula (infraspinatus fossa)
what is the insertion of INFRAspinatus?
humerus (GT)
what is the action of infraspinatus?
provides stabiliy
externally rotates armh
what is the innervation to infraspinatus?
supra scapular nerve
what is th origin of teres minor?
scapula (dorsolateral)
what is the insertion of teres minor?
humerus (GT)
what is the action of teres minor ?
provides stability
external rotation of arm
what is the innervation to teres minor?
axillary nerve
what are the borders of the triangular interval?
superior - teres major
medial - triceps (long head)
lateral - triceps (lateral head)
what are the structures in the triangular interval?
radial nerve
deep artery of the arm (profound brachii)
what are the borders of the triangular space?
superior - teres minor
inferior - teres major
lateral - triceps (long head)
what structures are within the triangular space?
circumflex scapular aretry
what are the borders of the quadrangular space?
superior - teres minor
inferior - teres major
medial - triceps (long head)
lateral - humerus (medial border)h
what are the structures in the quadrangular space?
axillary nerve
posterior circumflex artery
humeral artery
how many parts are there to the axillary artery and what divides it?
3 parts
pec minor
what are the branches of the axillary artery?
screw the lawyer save a patient
I superior thoracic artery
II thoracoacromial artery, lateral thoracic artery
III subscapular artery, anterior humeral circumflex artery, posterior humeral circumflex artery
what is the largest branch of the axillary artery?
subscapular
what is the course of the superior thoracic artery?
medial to serrates anterior and pec muscles
what is the course of the thoracoacromial artery?
four branches
1. deltoid
2. acromial
3. pectoralis
4. clavicular
(DAB C)
what is the course of the lateral thoracic artery?
descends to serrates anterior
what is the course of the subscapular artery?
two branches, thoracodorsal and circumflex scapular (triangular space)
what is the course of the anterior humeral circumflex artery?
blood supply to the humeral head: arcuate artery lateral to bicipital groove
what is the course of the posterior humeral circumflex artery?
branch in the quadrangular space accompanying the axillary nerve
what is the surface marking of the coracoid?
2cm inferior to the junction between the middle and lateral thirds of the clavicle
structures attaches to the coracoid process?
ligaments (3)
1. coracoclavicular (trapezoid/conoid)
2. coracohumeral
3. coracoacromial
muscles (3)
1. pec minor (insertion)
2. coracobrachialis (origin)
3. short head of biceps (origin)
muscles inserted in the bicipital groove?
PLT sandiwch
teres major (medial lip)
latisimus dorsi (floor)
pec major (lateral lip)
*tendon of long head of biceps runs in the groove
which muscles cause shoulder joint abduction?
supraspinatus (0-15 degrees)
deltoid middle fibres (15-90 degrees)
trapezius and serrates anterior over 90 degrees (upward rotation of the scapula and lateral rotation of humerus)
factors decreasing the stability of the shoulder joint?
shallow glenoid
lax capsule with few ligaments
interior aspect not supported due to presence of quadrangular space
main stabiliser of the shoulder?
rotator cuff muscles
what static restraints stabilise the shoulder?
GAANG-C
glenoid labrum
articular version
articular conformity
negative intra-articular pressure
capsule (posterior capsule and rotator interval)
glenohumeral ligaments
what are the dynamic restraints of the shoulder?
joint concavity compression (rotator cuff)
proprioception
what are synovial joints?
freely moving joints, articulating bony surfaces are covered in hyaline articular cartilage and separated by synovial fluid (lubricant)w
what does synovial fluid do?
lubrication
aids metabolite transport into cells
what is synovial fluid made by ?
synovial membrane
what does the axillary nerve give motor and sensory supply to ?
motor: teres minor, deltoid
sensory - lower half deltoid (regimental patch)
